Direct from SINTEF's web site:

"Small but tightly packed

The microphone is packed full of microelectronics. What makes it really special, however, is an optical position sensor that is no more than a millimetre in diameter.

The reason for giving a position sensor such an important role is that a microphone is completely dependent on a membrane, which picks up the pressure waves produced by the sound.

“In principle, a microphone acts like a drum. You have a membrane that vibrates when it is impacted by a sound – which is just a series of pressure waves. And then you have a reference surface in the background. The distance between these two surfaces registers the sound. We do this by measuring light waves from a microscopically small laser, so we can say that the sensor in microphones actually sees the sound,” explains Lacolle.

The sensor can measure incredibly small movements, and thus also extremely quiet sounds. If we make the membrane light enough, and let it oscillate freely in the air, the microphone also becomes directionally sensitive. “That also tells us where the sound is coming from,” says Lacolle, adding that the membrane is only 100 nanometres thick, almost 1000 times thinner than a human hair.

Coloured by light

The technology that makes the microphone so sensitive is based on a combination of two optical phenomena; interference and diffraction, both of which are due to the wave character of light.

“If we hold up a CD to the light, we see the play of colours where it reflects the light. This happens because light consists of a spectrum of wavelengths that the naked eye perceives as colours, and these wavelengths are diffracted in different directions, explains Lacolle.

Another phenomenon that can be utilised to measure sound is interference, which occurs when a number of waves are superimposed on each other. You can observe this when you stand in a harbour where incoming waves are reflected by a pier and are superimposed on top of the waves that follow them into the harbour. Complex, apparently chaotic wave patterns can occur, but so do standing waves, which don’t appear to move at all,” says the SINTEF researcher."

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"One ton of natural uranium can produce more than 40 million kilowatt-hours of electricity."

Em 2011, foram produzidos 52.460 GWh de energia eléctrica em Portugal, sendo que 30.697 GWh tiveram origem em combustível fóssil.

As nossas 7000 Ktons de reservas, ao nível actual de consumo, serviriam pois para, mais coisa menos coisa, 9 anos!

De notar que, relativamente às reservas de Urânio, este ser apenas um valor estimado, pois que certezas quanto às reais quantidades só as poderiamos ter fruto de um trabalho de prospeção do subsolo português que, como se sabe, não existe.

Historic data from many countries demonstrate that on average no more than 50–70% of the uranium in a deposit could be mined. An analysis of more recent data from Canada and Australia leads to a mining model with an average deposit extraction lifetime of 10 ± 2 years. This simple model provides an accurate description of the extractable amount of uranium for the recent mining operations.

Using this model for all larger existing and planned uranium mines up to 2030, a global uranium mining peak of at most 58 ± 4 ktons around the year 2015 is obtained. Thereafter we predict that uranium mine production will decline to at most 54 ± 5 ktons by 2025 and, with the decline steepening, to at most 41 ± 5 ktons around 2030. This amount will not be sufficient to fuel the existing and planned nuclear power plants during the next 10–20 years. In fact, we find that it will be difficult to avoid supply shortages even under a slow 1%/year worldwide nuclear energy phase-out scenario up to 2025. We thus suggest that a worldwide nuclear energy phase-out is in order. If such a slow global phase-out is not voluntarily effected, the end of the present cheap uranium supply situation will be unavoidable. The result will be that some countries will simply be unable to afford sufficient uranium fuel at that point, which implies involuntary and perhaps chaotic nuclear phase-outs in those countries involving brownouts, blackouts, and worse.

Michael Dittmar, "The end of cheap Uranium", Science of The Total Environment

Segundo a Wikipedia, as reservas de Urânio em Portugal estão estimadas em 7 kTon.

Ora isso, em kWh, dará para quanto?